XML 115 R81.htm IDEA: XBRL DOCUMENT v3.19.1
Revenue (Details)
 3 Months Ended 6 Months Ended
Mar. 31, 2019
USD ($)
Customers
percent
Mar. 31, 2018
USD ($)
Mar. 31, 2019
USD ($)
Customers
percent
Mar. 31, 2018
USD ($)
State [Line Items]        
Revenue Capitalized During Pre-Commercial Operations $ 0 $ (10,000,000) $ 0 $ (11,000,000)
Electric revenue (2,712,000,000) (2,761,000,000) (5,392,000,000) (5,269,000,000)
Sales of Electricity 2,712,000,000 2,753,000,000 5,393,000,000 5,262,000,000
Off System Sales of Electricity 0 2,000,000 1,000,000 4,000,000
Other revenue $ 38,000,000 39,000,000 $ 82,000,000 79,000,000
Total number of customers 154   154  
Total long duration contract revenue recognition 2,514,000,000   4,981,000,000  
Total number of customers that represent a percent of sales | percent 1   1  
Revenues $ 2,750,000,000 2,792,000,000 $ 5,475,000,000 5,341,000,000
ALABAMA        
State [Line Items]        
Electric revenue (387,000,000) (406,000,000) (779,000,000) (767,000,000)
GEORGIA        
State [Line Items]        
Electric revenue (70,000,000) (73,000,000) (137,000,000) (136,000,000)
KENTUCKY        
State [Line Items]        
Electric revenue (173,000,000) (174,000,000) (341,000,000) (333,000,000)
MISSISSIPPI        
State [Line Items]        
Electric revenue (249,000,000) (252,000,000) (501,000,000) (489,000,000)
NORTH CAROLINA        
State [Line Items]        
Electric revenue (21,000,000) (20,000,000) (41,000,000) (36,000,000)
TENNESSEE        
State [Line Items]        
Electric revenue (1,799,000,000) (1,822,000,000) (3,568,000,000) (3,482,000,000)
VIRGINIA        
State [Line Items]        
Electric revenue $ (13,000,000) $ (14,000,000) $ (25,000,000) $ (26,000,000)
20-year Termination Notice [Member]        
State [Line Items]        
Number of customers | Customers 3   3  
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block]     67  
Number of customers that represent the percent of sales | percent 0   0  
Revenues $ 34,000,000      
15-year Termination Notice [Member]        
State [Line Items]        
Number of customers | Customers 11   11  
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block]     251  
Number of customers that represent the percent of sales | percent 0   0  
Revenues $ 127,000,000      
12-year Termination Notice [Member]        
State [Line Items]        
Number of customers | Customers 1   1  
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block]     12  
Number of customers that represent the percent of sales | percent 0   0  
Revenues $ 6,000,000      
10-year Termination Notice [Member]        
State [Line Items]        
Number of customers | Customers 52   52  
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block]     1714  
Number of customers that represent the percent of sales | percent 0   0  
Revenues $ 862,000,000      
6-year Termination Notice [Member]        
State [Line Items]        
Number of customers | Customers 1   1  
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block]     25  
Number of customers that represent the percent of sales | percent 0   0  
Revenues $ 13,000,000      
5-year termination notice [Member]        
State [Line Items]        
Number of customers | Customers 86   86  
Long-Duration Contracts Revenue Recognition, Policy [Policy Text Block]     2912  
Number of customers that represent the percent of sales | percent 1   1  
Revenues $ 1,472,000,000